A wide variety of mechanical refrigeration systems are currently in use in a wide variety of applications. Those familiar with mechanical refrigeration systems recognize that such systems require servicing periodically. This servicing often takes the form of the addition of refrigerant into the system to replace refrigerant which has escaped from the system. Before adding refrigerant, it is often necessary to evacuate the refrigerant remaining in the system. Typically, this remaining refrigerant is removed by bleeding the refrigerant off to the atmosphere.
In recent years, much concern has arisen about this practice of releasing fluorocarbon based refrigerants into the atmosphere. It is believed that the release of such fluorocarbons depletes the concentration of ozone in the atmosphere. This depletion of the ozone layer is believed to adversely impact the environment and human health.
To avoid releasing fluorocarbons into the atmosphere, devices have been constructed that are designed to recover the refrigerant from the refrigeration system. These refrigerant recovery devices often include means for processing the refrigerant so recovered so that the refrigerant can be reused.
Currently, several companies are involved in the manufacture and development of refrigerant recovery devices. These companies include K-Whit Tools, Inc., the assignee of the instant application, the ROBINAIR Manufacturing Corporation (later known as Kent-Moore Corporation), The Draf Tool Co., Inc., and the Murray Corporation.
Examples of products developed by K-Whit Tools, Inc., include the devices disclosed in U.S. Pat. No. 4,942,741 and U.S. patent application Ser. No. 07/579,779, both of which were invented by the inventors of the instant application, John P. Hancock and Ralph A. McClelland.
Examples of devices originating from ROBINAIR include those shown in Cain U.S. Pat. No. 4,261,178; Cain U.S. Pat. No. 4,363,222; Lower, et al. U.S. Pat. No. 4,441,330; Manz, et al. U.S. Pat. Nos. 4,768,347; 4,805,416; 4,809,520; and 4,938,031; and Punches et al U.S. Pat. No. 4,878,356.
An example of a device developed by Draf Tools Co., is shown in Koser U.S. Pat. No. 4,285,206. Koser discloses a device which both reclaims refrigerant, and is capable of providing fresh refrigerant for recharging the refrigeration system once evacuated. An example of a device developed by the Murray Corporation is shown in Proctor, et al. U.S. Pat. No. 4,909,042.
In addition to those devices developed by the organizations discussed above, several others have developed refrigerant recovery devices. Examples of these other devices are shown in Sparano U.S. Pat. No. 3,232,070; Massengale U.S. Pat. No. 3,357,197; Owen U.S. Pat. No. 4,110,998; Goddard U.S. Pat. No. 4,476,688: Margulefsky et al. U.S. Pat. Nos. 4,480,446 and 4,554,792; Staggs et al. U.S. Pat. No. 4,539,817; Taylor U.S. Pat. No. 4,646,527; and Lounis U.S. Pat. No. 4,862,699.
The patents discussed above are of interest in that they disclose a wide variety of devices for removing refrigerant from a refrigeration system, and processing the refrigeration so recovered. Some of the devices, such as the device shown in Manz et al U.S. Pat. No. 4,805,416 include a recycling loop wherein refrigerant that is withdrawn from a refrigeration system can be recycled through the purification loop of the recovery device to further purify the refrigerant. Other devices such as that shown in Cain U.S. Pat. No. 4,261,178 are primarily "single pass" devices wherein whatever processing is done to the refrigerant is done in a single pass of the refrigerant from the refrigeration system, through the device, and into the storage or disposal tank.
Although some, if not all of the devices discussed above are capable of removing and processing refrigerant, room for improvement exists. In particular, room for improvement exists in producing a more simple device which performs its intended function with less complexity than some prior known devices. Another area for improvement resides in providing a more simple oil separator and filter apparatus for use in a refrigerant recovery device.
It is therefore one object of the present invention to provide a refrigerant recovery device that provides a relatively simple, yet effective means for recovering refrigerant from a refrigeration system, and processing the refrigerant so recovered.